Each of these structures is a way to encapsulate a drug, such as CBD, in a lipophilic (fat-loving) core with an outside layer of hydrophilic (water-loving) molecules. This outer layer forms a barrier around the CBD molecules to delay their metabolism in the human digestive system.
Nanoparticles are tiny clusters of CBD molecules that are surrounded by a fatty acid. The lipophilic end of the fatty acid aligns with the CBD cluster and the hydrophilic end points to the outside surface. Think of this as a bicycle wheel. The CBD cluster is the wheel hub; the fatty acid is the spokes; the lipophilic end attaches to the hub and the hydrophilic end attaches to the tire rim. Nanoparticles are small enough (~1-5 x 10-7 meters) to be absorbed in the small intestine. These invisible particles remain suspended in water-based liquids, making them a great way to add CBD to drinks.
Micelles are similar in size to nanoparticles but have a different formation and delivery processes. Like nanoparticles, micelles have an inner lipophilic core and an outer hydrophilic shell. CBD molecules, as well as terpenes and other cannabinoids, can dissolve in the inner core. Micelles aren’t necessarily round and can be cylindrical or an irregular shape. Micelles also can be formed from larger polymers and contain several layers of molecules. Surfactants form the micelle structure that solvates CBD and helps emulsify or mix the CBD into hydrophilic body fluids. An interesting feature of micelles is that they can deliver multiple therapeutic compounds to a site. The outer surfactant can be chosen to selectively interact with specific enzymes and proteins to target different types of cells.
Liposomes are typically larger than nanoparticles and micelles. The liposome structure consists of 2 lipid bilayers with an inner aqueous solution. Think of it as a donut with the inner hole being filled with hydrophilic molecules and lipophilic or fatty molecules in the outer ring. The liposome can either fuse to a cell surface to deliver drugs or the cell, in a process known as endocytosis, can swallow the liposome. This targeted delivery of the liposome to cell walls allows it to bypass metabolism in the gastrointestinal tract.